1. Field of the Invention
This invention relates to improvements in a vibration insulating pad through which two vibratory members are supportingly connected, and more particularly to such a vibration insulating pad which is formed of rubber and disposed in a hole formed in a member for supporting a power unit of an automotive vehicle.
2. Description of the Prior Art
It is well known that there are automotive vehicles provided with a center member on which a power unit is supported. The center member is disposed extending in the fore-and-aft direction of the automotive vehicle and elastically supported through vibration insulating pads to a vehicle body or frame. Each vibration insulating pad is fitted in an installation hole formed in the center member.
The vibrating insulating pad is formed of rubber and generally cylindrical so as to be formed with an axially extending through-hole. The pad includes head, neck and body sections. The head section is formed tapered to facilitate installation of the pad in the installation hole of the center member. A generally annular groove is formed between the head and body section and around the neck section.
However, difficulties have been encountered in the above conventional vibration insulating pad as discussed below. The vibration insulating pad is relatively low in spring constant to obtain a sufficient vibration insulating effect, which requires making the pad large-sized to meet a necessary durability of the pad. Thus, the head section is considerably larger in diameter than the installation hole of the center member and therefore it is impossible to install the pad into the installation hole even upon deforming it by hands of an operator. In this regard, a pad press-fitting facility such as an air cylinder is required for the installation operation for the pad. This is disadvantageous from the view points of reducing the number of steps in a production process and of production cost for a power unit supporting system.